some have none, but have a differentiated membrane called a periplast (unarmored; noctiluca is one species like this)

Most have a cell wall composed of cellulose plates located in vesicles to the inside of the plasma membrane (not outside like other cell walls)--> Armored

Where are the flagella located? HOw many?

two flagella located in perpendicular grooves; they have a groove that flagella lies in as it circles the organism. A second groove is smaller, with the other lying in it (the other flagella is longer than the groove causing it to stick out)

as opposed to a euk, whose chromosomes condense in prophase, the mesokaryotic dinoflagellates stay condensed throughout.

This makes them prokaryotic like. Their DNA is not associated with histones like eukaryote. (no histones in dinoflag. and few proteins)

Why is there a divide in what dinof are classified as?

some considered to be protozoa

people say algae partly because half are autotrophic and the other half are heterotrophic

Other dinoflagellates have both __.

Explain reproduction.

mesokaryotic and eukaryotic

asexual (divide by mitosis)

difference: nuclear envelope persists instead of disintegrating. The chromosomes attach to it as channels of cytoplasm inavde the nucleus and have microtubules; no mitotic spindle

Habitat?

most marine, usually in warm water, but not always

some freshwater (Lake Erie)

Pigments?

chl a and c

like diatoms, several carotenoids (golden brown); alot are reddish

Cell wall __ is different.

What happens to the cell wall during division?

placement

the cell wall gets split

-each daughter cell gets half and has to grow the other part

- some plates, not all

Sexual reproduction?

What do dinoflagellates cause?

not common

for those wh do the only diploid is the zygote

red tide; can multiply explosively

Dinoflagellates are important as __. They like __, but can __.

Some are __. What value does this have?

Some live __.

the base of the food chain

warmer water

live in cool water

bioluminescent; to confuse predators; it occurs when they are agitated

in other organisms; gives coral its color and food; no cell wall as it functions as chloroplast

Explosive population growth of dinoflagellates produces __ (not really __; doesn't always have to be __; some are __)

Causes?

red tides

tides

red

colorless

nutrients in excess, temp, current, wind patters etc.

Health problems in people can be caused by the production of __ (released when __) and sometimes __ (secreted by __) by some species of __. The most common genera involved are __, __, and __.

endotoxins

the cells die

exotoxins

living cells

dinof.

Gymnodinium

Alexandrium

Dinophysis

In most cases, __ are the direct source of the toxins for people. They feed by __ and __. When the __ is toxic dinoflagellates, the __ accumulate the toxins. The toxins have no adverse effect on the shellfish. Other animals, including people which eat the shellfish may be affected by the toxins. The toxins are not _ to all organisms. More __ are toxic than __.

Initial: Diarrhea, vomiting, ab pain
Later: neurological dysfunction, including numbness and tingling around the mouth, hands, and feet; joint and muscle pains with weakness and cramps; dizziness; anxiety; sweating; headache; and reversal of temperature sensation, where cold feels hot and vice versa; heart arrhythmia; paralysis and death have been documented, but symptoms are usually less severe

Treatment:

no antidote; supportive; patient has stomach pumped and decontaminated with charcoal; treatment with mannitol may relieve some symptoms; recovery time variable and may take weeks, months, or years. Survivors do recover

__ is a newly discovered dinoflagellate that has at least __ in its life cycle. Many of the stages are __, while several are __. Several __ have also been found.

Sometimes, it looks like a __; sometimes, it does not.

pfiesteria piscicida (means fish killer)

22 identified stages

amoeboiid

biflagellated

cyst stages

dinoflagellate

Pfiesteria piscida is the only dinof. knwon to produce high amounts of __.

It is the only toxic dinoflagellate knonw to show __ to targeted finfish or shellfish prey, hence the names __ and __. This occurs in response to an unidentified substance in fish __. When threshold concentrations of these substances are detected, the dinoflagellates do what?

exotoxins

direct, "deliberate" chemosensory response

killer alga and ambush predator

secreta/ excreta

swim up into the water and excrete the eotoxins (sits in the sediments until the fish comes)

Several stages, including both __ and __, are toxic to __ and __. A small __ is the most toxic.

Effects on fish: __

flagellated and amoeboid forms

finfish and shellfish

flagellated vegetative form

the toxins induce the formation of open ulcerative sores, hemorrhaging, and death

Effects on humans of Pfiesteria piscida : The toxins can be absorbed from __ or __. Known effects have come from exposure to the aerosols from dilute lab cultures of the organism's toxic stages or direct contact with the culture medium.